Numerous mutations in the human KCC2 protein are associated with the development of epilepsy (Järvelä et al., 2024; Kahle et al., 2014; Puskarjov et al., 2014; Saito et al., 2017; Saitsu et al., 2016; Stödberg et al., 2015). Here, SLC12A5 is linked to epilepsy.